Так. M((-1-12)/2;(8-1)/2)=(-13/2;7/2) |AM|=√((7-13/2)²+(-4-7/2)²)=√(1/4+121/4)=½•√122≈5.52 |AB|=√((3-5)²+(5-6)²+(1-3)²)=√(4+1+4)=3
Так.
M((-1-12)/2;(8-1)/2)=(-13/2;7/2)
|AM|=√((7-13/2)²+(-4-7/2)²)=√(1/4+121/4)=½•√122≈5.52
|AB|=√((3-5)²+(5-6)²+(1-3)²)=√(4+1+4)=3